Spacecraft capture mechanism

Abstract

The present invention provides a capture mechanism for capturing and locking onto the Marman flange located on the exterior surfaces of spacecraft/satellites. The capture mechanism achieves its goal of quickly capturing a target spacecraft by splitting the two basic actions involved into two separate mechanisms. One mechanism performs the quick grasp of the target while the other mechanism rigidises that grasp to ensure that the target is held as firmly as desired. To achieve a speedy grasp, the grasping action is powered by springs and an over-centre mechanism triggered either mechanically by a plunger or electronically by sensors and a solenoid. This forces two sets of jaws, one on either side of the object to be grasped, to close quickly over the target object. The jaws can be set up to grasp gently, firmly, or even not close completely on the target. The key is that they must close tightly enough so that the protrusions on the target cannot escape from the jaws due to any possible motions of the target. Once the jaws have sprung shut, a second mechanism draws the jaws (and their closing mechanism) back into the body of the tool pulling the captured target onto two rigidisation surfaces. The mechanism keeps pulling backwards until a pre-established preload is reached at which point the target is considered suitably rigidised to the capture mechanism.

Therefore what is claimed is: 
     
       1. A satellite capture mechanism for capturing a bracket mounted to a spacecraft or satellite, comprising:
 a) a first housing section, a quick grasp mechanism mounted in said first housing section, said quick grasp mechanism including
 clamping jaws having proximal sections pivotally mounted to a front portion of said first housing section and extending outwardly from a front of said first housing section, said clamping jaws configured to be sprung closed, 
 a biasing mechanism located in said first housing section configured for biasing distal sections of the clamping jaws apart, the biasing mechanism including an elongate plunger mounted for reciprocal movement along an axis of the first housing section, the biasing mechanism including a cam mechanism pivotally mounted to said elongate plunger and configured to have a cam portion engage said clamping jaws to bias the distal sections of the clamping jaws apart when the elongate plunger is fully extended forward of the first housing section, the cam mechanism being configured so that when the elongate plunger contacts a bracket mounted to a spacecraft and is moved inwardly into said first housing section the cam mechanism pivots with respect to said elongate plunger causing the cam portions engaging said clamping jaws to move forward forcing the distal ends of the clamping jaws to pivot toward each other be sprung quickly and sufficiently shut around a portion of the bracket such that the feature cannot escape from said clamping jaws thereby achieving soft capture of the portion of the bracket; 
 
 b) a second housing section mounted to a back of said first housing section, a rigidisation mechanism mounted in said second housing section, said rigidizing mechanism being independently actuated from said quick grasp mechanism, said rigidisation mechanism including
 a pulling mechanism connected to the elongate plunger configured to draw the elongate plunger and the clamping jaws further into the first housing section, the first housing section and cam mechanism being configured so that as the clamping jaws are withdrawn into the first housing section the cam portions engaging said clamping jaws are biased closer together, the pulling mechanism being configured to further pull the clamping mechanism into said first housing until a portion of the bracket abuts up against a rigidisation bracket to thereby rigidize the captured spacecraft to the capture mechanism; and 
 c) a third housing, said first and second housings being reciprocally movable along a longitudinal axis of said third housing, said third housing including
 i) an extension mechanism for extending said first and second housing out of said third housing a predetermined distance, 
 ii) a retraction mechanism for drawing said first and second housings back into said third housing, and 
 iii) a locking mechanism for locking said first and second housings within said third housing. 
 
 
 
     
     
       2. The mechanism according to  claim 1  further including a locking mechanism to lock said first and second housings in said extended position. 
     
     
       3. The mechanism according to  claim 1  further including a counterweight reciprocally mounted for movement in said third housing and being configured to counteract forces generated when the first and second housings are extended from said third housing. 
     
     
       4. The mechanism according to  claim 1  wherein said extension mechanism includes a spring attached at one end to said third housing and attached at the other end to a back portion of said second housing, and including trigger mechanism for triggering the locking to allow the first and second housings to be extended from said third housing. 
     
     
       5. The mechanism according to  claim 4  wherein said retraction mechanism includes a cable and motor system mounted to said third housing with said cable being connected to said first and second housings, wherein activation of the motor withdraws the second and third housings back into the third housing. 
     
     
       6. The mechanism according to  claim 1  including a bearing assembly positioned between said connected first and second housings and said third housing to facilitate sliding motion of the first and second housings with respect to the third housing. 
     
     
       7. A method for capturing a feature on a free flying client spacecraft, comprising:
 manoeuvering a capture mechanism mounted on a servicer spacecraft into proximity to the feature on the free flying client spacecraft; 
 actuating grasping jaws on a quick grasp mechanism, forming part of the capture mechanism, to be sprung closed when the feature is within range of being grasped by the grasping jaws with the grasping jaws to be sprung quickly and sufficiently shut such that the feature cannot escape from said grasping jaws thus achieving soft capture of the feature; and 
 upon soft capture of the feature, actuating a rigidizing mechanism, forming part of the capture mechanism, independent of the quick grasp mechanism to draw the quick grasp mechanism and the soft captured feature into a housing until said soft captured feature abuts against a rigidisation surface located in the housing to rigidize the soft captured feature and free flying client spacecraft relative to said housing. 
 
     
     
       8. The method according to  claim 7 , wherein the capture mechanism capable is attached to a positioning mechanism and configured for positioning the capture mechanism into close proximity to the feature to trigger the quick grasp mechanism, and including a sensing system for ascertaining a relative position of the capture mechanism and the feature, including a computer control system connected to said sensing system and said positioning mechanism, and wherein the method comprises a remote operator communicating with the computer control system for remote teleoperator control, supervised autonomous control, or fully autonomous control of capture operations between the servicer spacecraft and the client satellite. 
     
     
       9. A method for remote releasible capture of a feature mounted on a client satellite, comprising:
 a) launching a servicing spacecraft into an orbit to bring it into close proximity to a client satellite to be serviced, the servicing spacecraft comprising
 propulsion, guidance and telemetry systems, 
 a satellite capture mechanism configured to releasibly capture the feature mounted on the client satellite, the satellite capture mechanism including a two stage grasping tool including
 i) a quick grasp mechanism having clamping jaws configured to be sprung closed, said quick grasp mechanism being mounted for movement in a housing, said quick grasp mechanism configured to clamp said feature when said feature is in close proximity to, and triggers said clamping jaws to be sprung quickly and sufficiently shut such that the feature cannot escape from said clamping jaws thus achieving soft capture of the feature; and 
 ii) a rigidizing mechanism, independently actuated from said quick grasp mechanism and configured to, upon completion of the soft capture of the feature, draw the quick grasp mechanism and the soft captured feature into said housing until said soft captured feature abuts against a rigidisation surface located in said housing to rigidize the soft captured feature and spacecraft relative to said housing; 
 
 a vision system configured to have a field of view containing a portion of the client satellite being releasibly captured, 
 a computer control system interfaced with the capture mechanism and programmed with instructions so that it can coordinate all the components that are involved in the capture process, and 
 a communication system configured to allow remote operation of said vision system, and said capture mechanism; and 
 
 b) maneuvering the servicer satellite into location in close proximity to the client satellite, and deploying the satellite capture mechanism and releasibly capturing the feature on the client satellite; 
 c) wherein said communication system is configured to communicate with said computer control system for remote teleoperation control or a mixture of teleoperator and supervised autonomy control of an approach of the servicer satellite to, and capturing of, the client satellite. 
 
     
     
       10. A satellite capture system mounted on a servicer spacecraft for capturing and releasing a client satellite, comprising:
 a) a satellite capture mechanism configured to releasibly capture a feature mounted on the client satellite, the satellite capture mechanism including a two stage grasping tool including
 i) a quick grasp mechanism having clamping jaws configured to be sprung closed, said quick grasp mechanism being mounted for movement in a housing, said quick grasp mechanism configured to clamp said feature when said feature is in close proximity to, and triggers said clamping jaws to be sprung quickly and sufficiently shut such that the feature cannot escape from said clamping jaws thus achieving soft capture of the feature; and 
 ii) a rigidizing mechanism, independently actuated from said quick grasp mechanism and configured to, upon completion of the soft capture of the feature, draw the quick grasp mechanism and the soft captured feature into said housing until said soft captured feature abuts against a rigidisation surface located in said housing to rigidize the soft captured feature and spacecraft relative to said housing; 
 
 b) a command and control system interfaced with said satellite capture mechanism, said command and control system being configured to control deployment of said satellite capture mechanism for capture of the feature on the client satellite, and subsequent release of the client satellite; and 
 c) a communication system configured to provide communication between said command and control system and a remote operator for remote teleoperator control, or a mixture of teleoperator control and supervised autonomy control, or fully autonomous control of capture and release operations between the servicer spacecraft and the client satellite. 
 
     
     
       11. The satellite capture system according to  claim 10  wherein said command and control system includes a computer control system mounted on the servicer spacecraft interfaced with said satellite capture mechanism, said computer control system being configured, and programmed with instructions, for control of capture and release operations between the servicer spacecraft and the client satellite.